Phenotypic Switching of Nonpeptidergic Cutaneous Sensory Neurons following Peripheral Nerve Injury

In adult mammals, the phenotype of half of all pain-sensing (nociceptive) sensory neurons is tonically modulated by growth factors in the glial cell line-derived neurotrophic factor (GDNF) family that includes GDNF, artemin (ARTN) and neurturin (NRTN). Each family member binds a distinct GFRα family co-receptor, such that GDNF, NRTN and ARTN bind GFRα1, -α2, and -α3, respectively. Previous studies revealed transcriptional regulation of all three receptors in following axotomy, possibly in response to changes in growth factor availability. Here, we examined changes in the expression of GFRα1-3 in response to injury in vivo and in vitro. We found that after dissociation of adult sensory ganglia, up to 27% of neurons die within 4 days (d) in culture and this can be prevented by nerve growth factor (NGF), GDNF and ARTN, but not NRTN. Moreover, up-regulation of ATF3 (a marker of neuronal injury) in vitro could be prevented by NGF and ARTN, but not by GDNF or NRTN. The lack of NRTN efficacy was correlated with rapid and near-complete loss of GFRα2 immunoreactivity. By retrogradely-labeling cutaneous afferents in vivo prior to nerve cut, we demonstrated that GFRα2-positive neurons switch phenotype following injury and begin to express GFRα3 as well as the capsaicin receptor, transient receptor potential vanilloid 1(TRPV1), an important transducer of noxious stimuli. This switch was correlated with down-regulation of Runt-related transcription factor 1 (Runx1), a transcription factor that controls expression of GFRα2 and TRPV1 during development. These studies show that NRTN-responsive neurons are unique with respect to their plasticity and response to injury, and suggest that Runx1 plays an ongoing modulatory role in the adult

Establishment risk from pet-trade freshwater turtles in the European Union

The pet-turtle market has grown in recent years and become an important pathway for the introduction of alien species in Europe. The import of Trachemys scripta elegans has been banned by European Commission Regulation due to its species’ expanding territory and negative impact on native species. Since the demand from hobby breeders persists, however, blocking imports of this popular subspecies opens up the possibility for the introduction of other potentially invasive turtles. We determined those turtle species most common in the pet trade within the Czech Republic, which is the most important producer, importer and exporter of ornamental aquatic animals in the EU. The determination of establishment risk for the EU as a whole was then individually evaluated for turtle species based on known establishment models. Chelydra serpentina, Apalone spinifera, Apalone mutica, and Sternotherus odoratus were considered most problematic, because these species have serious establishment risk and are imported to the EU in substantial numbers. Also localities in the EU were identified where probability is highest for establishment of non-native turtles

Imports of ornamental crayfish: the first decade from the Czech Republic’s perspective

The import of aquarium animals has been increasing worldwide in recent years. Despite its contribution to world trade and the economy, this trade also comprises one of the main pathways for the introduction of non-indigenous animals. In the past decade, crayfish has become a popular pet as well as a potential threat to the environment upon its escape or release. Since the Czech Republic is one of the world’s leading importer, exporter, and producer of aquatic ornamental animals, we prepared a detailed analysis of crayfish imports. The present paper provides a complete list of countries supplying ornamental crayfish and examines trends of their prices and imported quantities during the past decade (2003–2012). Indonesia has been identified as the leading supplier in recent years. The annual average price of imported crayfish has varied over the evaluated period within the range of €0.76–4.72 per individual and it is rising annually by €0.15. The quantity of live crayfish imported for aquarium purposes has not been affected significantly by the price per individual and it has grown rapidly. Therefore a constant monitoring of this pet trade sector is strongly recommended for the future

Establishment risk from pet-trade freshwater turtles in the European Union

The pet-turtle market has grown in recent years and become an important pathway for the introduction of alien species in Europe. The import of Trachemys scripta elegans has been banned by European Commission Regulation due to its species’ expanding territory and negative impact on native species. Since the demand from hobby breeders persists, however, blocking imports of this popular subspecies opens up the possibility for the introduction of other potentially invasive turtles. We determined those turtle species most common in the pet trade within the Czech Republic, which is the most important producer, importer and exporter of ornamental aquatic animals in the EU. The determination of establishment risk for the EU as a whole was then individually evaluated for turtle species based on known establishment models. Chelydra serpentina, Apalone spinifera, Apalone mutica, and Sternotherus odoratus were considered most problematic, because these species have serious establishment risk and are imported to the EU in substantial numbers. Also localities in the EU were identified where probability is highest for establishment of non-native turtles

Imports of ornamental crayfish: the first decade from the Czech Republic’s perspective

The import of aquarium animals has been increasing worldwide in recent years. Despite its contribution to world trade and the economy, this trade also comprises one of the main pathways for the introduction of non-indigenous animals. In the past decade, crayfish has become a popular pet as well as a potential threat to the environment upon its escape or release. Since the Czech Republic is one of the world’s leading importer, exporter, and producer of aquatic ornamental animals, we prepared a detailed analysis of crayfish imports. The present paper provides a complete list of countries supplying ornamental crayfish and examines trends of their prices and imported quantities during the past decade (2003–2012). Indonesia has been identified as the leading supplier in recent years. The annual average price of imported crayfish has varied over the evaluated period within the range of €0.76–4.72 per individual and it is rising annually by €0.15. The quantity of live crayfish imported for aquarium purposes has not been affected significantly by the price per individual and it has grown rapidly. Therefore a constant monitoring of this pet trade sector is strongly recommended for the future

European hub for invaders: Risk assessment of freshwater aquarium fishes exported from the Czech Republic

Background. The aquarium fish trade is characterized by an enormous number of species. Aquarium fish may have an impact on native biota by means of their invasiveness as well as through pathogen transfer. The Czech Republic has become a gateway for aquatic pets into the European Union. The aims of this study were to identify the most common aquarium fish species on the wholesale market, to estimate temperature suitability for seasonal (winter and summer) survival in the EU, and also to assess the invasiveness risk of the most common aquarium fishes with the strongest temperature matching. Materials and methods. Data on aquarium fish species, their origin, and availability from producers and traders based in the Czech Republic were collected based on all available sources. The target area was defined as all member states of the EU. Estimation of the temperature suitability for each species was done using Climatch 1.0 software. The Freshwater Fish Invasiveness Screening Kit (FISK) was employed for species with temperature suitability within the target area exceeding 10% in the coldest quarter of the year. Results. In total, 1118 fish species representing 51 families were identified. Thirty-three species belonging to 13 families were classified as “very common”. Three sources of origin were identified: domestic production within the EU, farm production outside the EU, and wild harvests in the region of origin. The major suppliers outside the EU are in south-east Asia. Only one common species originated from wild harvests. FISK scoring divided the 11 species evaluated as having the strongest temperature suitability in the EU (TSEU) into seven species bearing medium risk and four species representing high risk. The family Cyprinidae was the most frequently represented among all evaluated taxa (seven species), but the majority of high-risk fishes belonged to the family Poeciliidae (three species). The highest score was earned by Carassius auratus (Linnaeus, 1758). Conclusion. The risk potential of aquarium fishes most traded in the EU seems to be not alarming. Attention should be focused on the possibility of novel pathogen transfer to native aquatic biota as an important aspect of regulating the aquarium fish trade